Migrated forum with many invalid (bouncing) emails

After migrating an older forum turns out 20% of the users have invalid emails (detected using neverbounce). This causes horrible bounce reports that mess up my email delivery (get listed in spam filters fast), I’m using sendgrid and SES. I want to:

  • stop discourse or sendgrid/SES from trying to send mails to these invalid mails
  • keep the user accounts active because some of this users are active and know their username and password.

I could introduce the invalid mails into the sendgrid/SES spam emails but that would not stop discourse from trying to email them and also i can’t manually introduce 20k mails in the sendgrid’s spam section.

How can I solve this?


I typically deactivate all users after an import and make people reset their password to reactivate their account. If you don’t want to do that, then you could try doing something like deactivating only users who have visited the site in the past X months. Or deactivate all users who haven’t logged in to the new site.

See also Handling bouncing e-mails.